The present invention relates to the communications field, and discloses a data transmission method and device, so as to resolve a problem of low efficiency and excessively much power consumption when user equipment performs blind detection on a scheduling control channel. A specific solution is: receiving, by a first device, scheduling control channel length information, performing, by the first device, blind detection in a preset search space according to the scheduling control channel length information, and after detecting a scheduling control channel corresponding to the scheduling control channel length information, obtaining, by the first device, resource allocation information carried on the scheduling control channel. The present invention is applied to data transmission.